Yahya bin Jadah and I went in to see a man from the Ansar who was one of the companions of the Messenger. He said that a freedwoman of the family of Abdul-Muttalib was mentioned in the presence of the Messenger of Allah ﷺ, and it was said that she stood in prayer through the night and fasted by day.The Messenger of Allah ﷺ said, "But as for me, I sleep and I pray, I fast and I break my fast. Whoever follows my example belongs to me, and whoever turns away from my way does not belong to me. Every deed has a period of zeal followed by a period of slackening. Whoever's slackening leads him to an innovation has gone astray, and whoever's slackening keeps him within the Sunnah is rightly guided."
حدثنا يحيى بن سعيد حدثنا جرير عن منصور
دخلت أنا ويحيى بن جعدة على رجل من الأنصار من أصحاب الرسول قال ذكروا عند رسول الله ﷺ مولاة لبني عبد المطلب فقال إنها تقوم الليل وتصوم النهار قال فقال رسول الله ﷺ لكني أنا أنام وأصلي وأصوم وأفطر فمن اقتدى بي فهو مني ومن رغب عن سنتي فليس مني إن لكل عمل شرة ثم فترة فمن كانت فترته إلى بدعة فقد ضل ومن كانت فترته إلى سنة فقد اهتدى
Its isnad is sahih. It is found in Ibn Mubarak's Zuhd, 389, no. 1102, with this wording, and in Ibn Hibban, 170, no. 653, Mawarid. The hadith has already appeared with similar wording in the well-known hadith of the three men, and it is found in the Sahihayn.